Define a Datatable using conditional logic

Question

I want to render a datatable, but depending on the value of some variable the content will slightly change.

Ideally I would like to do something like this, to re-use some part of the code:

var DT1 = $('#myTable').DataTable( {
    ajax: {
        url: 'ajax_search',
        type: 'GET',
        data: {},
        dataSrc: "",
    },
    if (value == 'X'){
    columns: [
        {"data": "fields.X1"},
        {"data": "fields.X2"},
    ],
    columnDefs: [
        { className: 'text-center', targets: [1] },
        {
            targets: [0],
            class: 'text-center',
            orderable: true,
            render: function (data, type, row) {
                var button1 = '<a href="/x_page/" target="_blank"><u>'+data+'</u></a>';
                return button1;
            }
        },
    ],
    } else{
        columns: [
        {"data": "fields.Y1"},
        {"data": "fields.Y2"},
    ],
    columnDefs: [
        { className: 'text-center', targets: [1] },
        {
            targets: [0],
            class: 'text-center',
            orderable: true,
            render: function (data, type, row) {
                var button2 = '<a href="/y_page/" target="_blank"><u>'+data+'</u></a>';
                return button2;
            }
        },
    ],
    }
    order: [
        [0, 'asc']
    ],
    "pagingType": "numbers",
    dom: 'rtp',
});

But it does not work. Basically I just want to modify the columns and the columnDefs part based on some logic, the other parts will be the same in all the cases.

Is there a way to do that and reduce some code?

Right now the way I have this implemented is as follows (working, but probably not best practice):

if (condition1) {
  //  Entire table definition with all the code for condition1, without reusing any code
} else if (condition2) {
  //  Entire table definition with all the code for condition2, without reusing any code
} else {
  //  Entire table definition with all the code for conditionN, without reusing any code
}

But it seems extremely inefficient to me, isn't there a way to do it and reuse the common parts of the code?

Answer 1

When you use the function (row, type, val, meta) syntax for the columns.data initialization option, the row argument automatically receives the AJAX data of each row.

$('#example').DataTable({
    "columns": [
        { "data": function(row) {
            if(condition1) {
                return row.fieldX;
            } else if(condition2) {
                return row.fieldY;
            } else {
                // etc. 
            } 
          }
        }
     ] 
}) 

Anyway, you can see examples in the docs page I linked before

You can also look at this updated JSFiddle that uses both columns and columnDefs.